The spine is formed of a column of vertebrae that extends between the cranium and pelvis. The five sections of the spine are the cervical, thoracic, lumbar, sacral, and coccygeal regions. There are 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal vertebrae. Cervical, thoracic, and lumbar vertebra are separated from one another by intervertebral discs that absorb shock, allow for movement, and maintain appropriate spacing between the vertebrae. The main functions of the spine include providing skeletal support and protecting the spinal cord. Even slight disruptions to either the intervertebral discs or vertebrae can result in serious discomfort due to compression of nervous tissue within or extending from the spinal canal. If a disruption to the spine becomes severe enough, consequences may include pain, loss of sensation, paralysis, etc. . . . Thus, it is of great interest and concern to be able to both prevent and correct ailments of the spine.
Surgical intervention, when needed, for treating various spinal ailments often entails fixing two or more vertebrae relative to each other. Spinal fixation constructs often use a combination of rods, plates, pedicle screws and bone hooks for constructing a rigid framework and anchoring it to the affected vertebrae. The optimal configuration required for each patient varies according to the patient's anatomical characteristics, the specific ailment being treated, and surgeon preference, among other factors. At times, the strength and stability of these custom configurations may be compromised as a result of torsional forces placed on the rods that span two or more vertebrae.
Spinal cross connectors are often implanted horizontally between two vertical rods to provide extra stability and decrease the torsional forces acting upon the rods in the customized surgical construct. Implantation of some spinal cross connectors known in the prior art can be time-consuming because locking more than one locking mechanism is required. Needs still exist for modular spinal fixation systems and components that provide maximum strength and stability in an easy-to-use fashion.